A theoretical model of a new electrostatic transducer incorporating fluidic amplification

This article concerns the design of a new electrostatic transducer whose backplate consists of a series of drilled pipes. A new one-dimensional model is derived which considers the interaction of the membrane with the air load, the air cavities, and the drilled pipes in the backplate. Dynamic equations for the impedance in each component of the device are calculated analytically and connected using interface conditions of continuity of pressure and radiation conditions into the air load. The model is able to produce solutions to the mechanical impedance of the device and the displacement of the membrane as a function of the device's design parameters. Model results for the output pressure compare well with previous experimental data. The inverse problem of retrieving the design parameters for a desired output is discussed

A self-study of teaching teachers using Epistemic Insight

Epistemic Insight (EI), defined as knowledge about knowledge (Billingsley et al, 2018) examines how distinctive forms of disciplinary knowledge can interact providing solutions to real world problems Utilising an interdisciplinary approach EI seeks to critically examine the current subject compartmentalization in the school curriculum, which leads to a siloed nature of school education within the UK and as a consequence a siloed education for preservice teachers (Billingsley et al, 2024). In introducing EI to preservice science teachers, we have identified the need to examine our practice as science teacher educators by refining views on the nature of science. Adopting EI within our teaching challenged us as teacher educators to re-examine the structure of our programmes. By adopting EI’s framework of examining questions with an interdisciplinary focus, we identified that our views on the foundations of scientific knowledge are not aligned despite the experience of the authors in science teacher education. This finding is illuminating given recent neoliberal shifts to standardise teacher education in England as implemented through the market review of ITT that is currently scrutinising curriculum providers curriculum materials (Mutton & Burn, 2024). Thus, in this paper, we seek to problematise the nature of teaching teachers about EI. Berry (2008) reminds us that efforts to address problems using self-study do not lead to simple solutions. Introducing a self-study model that draws on the idea of the tension between the actions and intent of teaching about EI, we examine our practice as teacher educators critically to explore the differences in understanding the nature of science. Our self-study is framed by analysing podcasts that discussed the dissemination of EI across distinct initial teacher education courses. Triangulating this with lesson studies enabled us to examine how our views of the nature science manifest in teaching practices and illuminate the tension between actions and intent. This paper, therefore, examines how we use our engagement with EI as a research -informed pedagogic framework to prompt pedagogic practice as science teacher educators. We argue adopting EI as a pedagogic framework not only supports preservice teachers to critically examine the compartmentalisation of Education, but further promotes deeper epistemically insightful understanding of how individual disciplines are distinctive. This in turn refines the practice of teachers and teacher educators alike

Transforming teacher education - introducing ITE students to Epistemic Insight: a workshop

Epistemic insight is a curriculum and innovation research initiative transforming teacher programmes across England. Epistemic Insight (EI) means ' knowledge about knowledge' and in particular how knowledge is constructed within disciplines and how it interacts across them. This involves using techniques to examine disciplinary boundaries and encouraging students to think beyond their own subject. The epistemic insight initiative has a consortium of ITE providers who have worked with their students exploring real-world problems in an interdisciplinary way using epistemic insight tools and strategies. This enabled secondary ITE students of various specialisms to collaborate across disciplines enriching their learning and teaching practice. This workshop will present the work completed at St Mary’s University, The University of Leicester and Birmingham University. The lessons learnt and future directions will be studied. The workshop will give delegates an opportunity to explore resources used and discuss with consortium members how and why you may want to introduce you students to EI. Presenters: Adrian Warhurst, University of Leicester, Rob Campbell, St Mary’s University and Dr Agnieszka J. Gordon Canterbury Christ Church University (Consortium Lead

Effect of nitrogen source on the growth and yield of cereals

Non-Peer Reviewe

Systematic study of effect of cross-drafts and nozzle diameter on shield gas coverage

A shield gas flow rate of 15–20 L min21 is typically specified in metal inert gas welding, but is often adjusted to as high as 36 L min21 by welders in practice. Not only is this overuse of shield gas wasteful, but uncontrolled high gas flows can lead to significant turbulence induced porosity in the final weld. There is therefore a need to understand and control the minimum shield gas flow rate used in practical welding where cross-drafts may affect the coverage. Very low gas coverage or no shielding leads to porosity and spatter development in the weld region. A systematic study is reported of the weld quality achieved for a range of shield gas flow rates, cross-draft speeds and nozzle diameters using optical visualisation and numerical modelling to determine the shield gas coverage. As a consequence of the study, the shield gas flow has been reduced to 12 L min21 in production welding, representing a significant process cost saving and reduced environmental impact with no compromise to the final weld quality

Economic evaluation of a community based exercise programme to prevent falls

OBJECTIVE: To assess the incremental costs and cost effectiveness of implementing a home based muscle strengthening and balance retraining programme that reduced falls and injuries in older women. DESIGN: An economic evaluation carried out within a randomised controlled trial with two years of follow up. Participants were individually prescribed an exercise programme (exercise group, n=116) or received usual care and social visits (control group, n=117). SETTING: 17 general practices in Dunedin, New Zealand. PARTICIPANTS: Women aged 80 years and older living in the community and invited by their general practitioner to take part. MAIN OUTCOME MEASURES: Number of falls and injuries related to falls, costs of implementing the intervention, healthcare service costs resulting from falls and total healthcare service costs during the trial. Cost effectiveness was measured as the incremental cost of implementing the exercise programme per fall event prevented. MAIN RESULTS: 27% of total hospital costs during the trial were related to falls. However, there were no significant differences in health service costs between the two groups. Implementing the exercise programme for one and two years respectively cost $314 and$265 (1995 New Zealand dollars) per fall prevented, and $457 and$426 per fall resulting in a moderate or serious injury prevented. CONCLUSIONS: The costs resulting from falls make up a substantial proportion of the hospital costs for older people. Despite a reduction in falls as a result of this home exercise programme there was no significant reduction in healthcare costs. However, the results reported will provide information on the cost effectiveness of the programme for those making decisions on falls prevention strategies

MIG gas shielding : Economic savings without detriment to quality

Over the years a number of claims have been made related to potential savings of the shielding gas used in the MIG process. A number of work streams have been set up to consider such areas from a technical and economic standpoint. The use of small helium additions has particular benefits and despite an increase in unit cost, the overriding benefits are achieved in reduced manhour cost. A similar situation has been established when using a high frequency process to switch shielding gases during welding. The outcome from this was very similar to that already described. Overlaid on these has been the increasing use of a technique that visualises actual gas flow during welding by the use of laser backlighting. Some preliminary work in this area is described particularly related to the effect of drafts on the gas distribution. A recent development on the market place is a piece of equipment, which regulates the gas flow automatically and synchronously with the welding current. Gas savings in the region of 50-60% have been obtained. Data has been produced to illustrate these benefits. The potential benefit of developing a computational fluid dynamic model of the gas flow is also described, and early development stages of the model shown. However, there will always exist the very basic management need to minimise leaks from the gas delivery systems

Fate of fertilizer N and its reaction products when applied to forage in winter

Non-Peer Reviewe